Recently, fuel filler pipes face many technical challenges and have to cope with strict regulations on evaporative gas, and also satisfy compatibility with a lightweight material and biofuel according to CO2 regulations. Plastic as a material of fuel filler pipes is suitable as a lightweight material, but barrier properties of components in an injection part of a fuel tank according to change in a composition of gasoline fuel due to addition of bio-ethanol are still in under development. Since component materials of conventional fuel tank injection parts include nylon and rubber, the materials have superior barrier properties against conventional gasoline, but weak barrier properties against alcohol.
In addition, in many countries, there is a need for development of materials having superior barrier properties due to strengthening of laws and regulations on evaporative gas. The permissible level of evaporative gas is 10 mg or less (F/Neck Ass'y 30 mg) with respect to E0 in Korea, 100 mg (EURO IV) with respect to E10 in Europe, and 2.5 mg (EPA Regulation Level III) with respect to E10 in North America.
Meanwhile, since high density polyethylene (HDPE) conventionally used as a resin for blow molding has a fuel barrier property of 68 g·mm/m2/day which is not excellent, the HDPE may be used through formation of a multilayered structure with an ethylene vinyl alcohol copolymer (EVOH). However, expensive multiple extruders should be used to form a multilayered structure, and a design meeting blow extrudability is required.
Accordingly, nylon-based resins having superior barrier properties may be used. However, polyamide 6 among nylon-based resins has superior barrier properties against gasoline but unsatisfactory low-temperature impact properties.
Therefore, there is a need for development of a material which may be easily blow-molded, may enhance impact resistance, tensile strength and gas barrier properties, and may be applied to components of an injection part of a fuel tank.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.